Velocity based control process for a machine digging cycle

• US 7,979,181 B2
• Filed: 03/09/2007
• Issued: 07/12/2011
• Est. Priority Date: 10/19/2006
• Status: Active Grant

• Current Assignee: Caterpillar Incorporated
• Original Assignee: Caterpillar Incorporated
• Inventors: Magstadt, Chad, Alshaer, Bassam J., Mettlach, Gregory, Clark, Megan, Price, Robert J.
• Primary Examiner(s): Tran; Dalena
• Application Number:
  US11/716,453
• Publication Number:
  US 20080097672A1
• Time in Patent Office: 1,586 Days
• Field of Search: 701/50, 414/710, 414/697, 414/699, 414/685, 172/2, 172/4, 172/4.5, 172/18, 379/07, 373/42, 373/48, 374/19, 374/14, 373/47, 373/14, 373/19, 374/17
• US Class Current: 701/50
• CPC Class Codes: E02F 3/434 providing automatic sequences of movements, e.g. automatic dumping or loading, automatic return-to-dig
• CPC Class Codes: E02F 3/437 providing automatic sequences of movements, e.g. linear excavation, keeping dipper angle constant
• CPC Class Codes: E02F 9/2029 Controlling the position of implements in function of its load, e.g. modifying the attitude of implements in accordance to vehicle speed control for hydraulic or pneumatic drives E02F9/2203, E02F9/2221 and E02F9/2253 take precedence

Abstract

A method and machine with an automated digging cycle is provided. The method includes moving an implement system of the machine through a work cycle, including interacting with a material. The method further includes sensing values associated with a bucket velocity parameter, such as bucket tip velocity, during interacting with the material, and controlling the velocity parameter via commands which control a sequence of bucket orientations whereby an implement system of the machine interacts with the material, responsive to the sensed values. The machine includes an electronic controller configured via a control algorithm to execute the automated digging cycle. A velocity based control system for an excavating machine includes an electronic controller configured to receive velocity signals from at least one sensor, determine a bucket tip velocity, and output control commands to move a bucket of the excavating machine through a material via a sequence of bucket orientations that is based on the determined bucket tip velocity.

Claims

1. A method of controlling a machine having an implement system including a linkage and a bucket coupled with the linkage, comprising the steps of:

moving the implement system through a work cycle that includes interacting with a material;

sensing values associated with a bucket velocity parameter during interacting with material; and

controlling the bucket velocity parameter by controlling a sequence of bucket orientations whereby the implement system interacts with the material;

wherein the step of controlling the bucket velocity parameter includes outputting actuator control commands for at least one actuator of the implement system with an electronic controller of the machine, responsive to a hardness of the material indicated by the sensed values.

2. The method of claim 1 wherein the machine comprises an excavating machine, and wherein the moving step comprises moving the implement system through an automated digging cycle.

3. The method of claim 2 wherein the sequence of bucket orientations whereby the implement system interacts with material defines a bucket tip path, and wherein the step of controlling the bucket velocity parameter comprises outputting commands to at least one actuator of the implement system to control the bucket tip path during interacting with material.

4. The method of claim 2 wherein:

the step of sensing values associated with a bucket velocity parameter further comprises the steps of sensing values indicative of boom actuator velocity, sensing values indicative of stick actuator velocity and sensing values indicative of bucket actuator velocity;

the method further comprises a step of determining a bucket tip velocity based on the sensed values; and

the step of controlling the bucket velocity parameter includes outputting velocity commands to actuators for the implement system to vary a sequence of bucket orientations whereby the implement system interacts with material responsive to the determined bucket tip velocity.

5. The method of claim 2 wherein the step of controlling the bucket velocity parameter further comprises the steps of, controlling a boom-up parameter and controlling a bucket-curl parameter.

6. The method of claim 5 wherein the step of controlling the bucket velocity parameter further comprises a step of controlling a digging pass distance of the bucket through the material responsive to the sensed values.

7. The method of claim 6 wherein the step of controlling the bucket velocity parameter further comprises the steps of:

commanding relatively faster bucket-curl and relatively slower boom-up in the digging cycle, if the material is relatively softer; and

commanding relatively slower bucket-curl and relatively faster boom-up in the digging cycle, if the material is relatively harder.

8. The method of claim 7 wherein the step of moving the implement system comprises incrementally decreasing at least one of boom-up and bucket-curl commands, if bucket tip velocity is above a desired velocity.

9. The method of claim 2 further comprising a step of determining a target bucket tip velocity for moving the implement system in the automated digging cycle, based at least in part on a power interaction of the bucket with material.

10. A machine comprising:

an implement system that includes a linkage having a boom and a stick, a bucket, and a plurality of actuators;

at least one sensor configured to sense values associated with a bucket velocity parameter; and

an electronic controller coupled with said at least one sensor and with each of said actuators, said electronic controller being configured to control the bucket velocity parameter by controlling a sequence of bucket orientations whereby the implement system interacts with a material responsive to a hardness of the material indicated by signals from said at least one sensor.

11. The machine of claim 10 wherein said at least one sensor comprises a sensor group including a plurality of sensors coupled one with each of said plurality of actuators, said electronic controller being configured to control bucket tip velocity responsive to a material hardness indicated by inputs from said plurality of sensors.

12. The machine of claim 10 comprising an excavating machine.

13. The machine of claim 12, wherein said electronic controller is configured via an automated digging cycle control algorithm to control the bucket velocity parameter via commands to at least one of said actuators to vary a sequence of bucket orientations in a digging portion of an automated digging cycle.

14. The machine of claim 13 wherein said plurality of actuators includes a boom actuator, a stick actuator and a bucket actuator, wherein said plurality of sensors includes a boom sensor, a stick sensor and a bucket sensor, and wherein said electronic controller is further configured via said control algorithm to determine bucket tip velocity based on inputs from said sensors and responsively output bucket-curl, stick-in and boom-up control commands to said bucket, stick and boom actuators to vary said sequence of bucket orientations responsive to determined bucket tip velocity.

15. The machine of claim 14 wherein said electronic controller is further configured via said control algorithm to command relatively faster bucket-curl and relatively slower boom-up, where bucket tip velocity is relatively greater, and configured to command relatively slower bucket-curl and relatively faster boom-up where bucket tip velocity is relatively less.

16. A control system for an excavating machine having an implement system that includes a linkage with a boom and stick, and a bucket, said control system comprising:

at least one sensor configured to output signals indicative of a bucket velocity parameter; and

an electronic controller coupled with said at least one sensor, said electronic controller being configured to control the bucket velocity parameter by controlling a sequence of bucket orientations whereby said implement system interacts with a material responsive to a hardness of the material indicated by signals from said at least one sensor.

17. The control system of claim 16 wherein said at least one sensor is configured to output signals indicative of bucket tip velocity, said electronic controller being configured to determine bucket tip velocity based on said signals, said electronic controller being further configured to output a sequence of velocity commands to at least one actuator of the implement system during digging material with said bucket, and configured to vary velocity commands within the sequence responsive to determined bucket tip velocity.

18. A control system for an excavating machine having an implement system that includes a linkage with a boom and stick, and a bucket, said control system comprising:

at least one sensor configured to output signals indicative of a bucket velocity parameter; and

an electronic controller coupled with said at least one sensor, said electronic controller being cg to control the bucket velocity parameter by controlling a sequence of bucket orientations whereby said implement system interacts with material responsive to signals from said at least one sensor;

wherein said at least one sensor is configured to output signals indicative of bucket tip velocity, said electronic controller being configured to determine bucket tip velocity based on said signals, said electronic controller being further configured to output a sequence of velocity commands to at least one actuator of the implement system during digging material with said bucket, and configured to vary velocity commands within the sequence responsive to determined bucket tip velocity; and

wherein said electronic controller is further configured to output increased velocity commands to a bucket actuator of the implement system where bucket tip velocity is relatively greater and output decreased velocity commands to a bucket actuator where bucket tip velocity is relatively less.

19. The control system of claim 18 wherein said electronic controller is further configured to output decreased velocity commands to a boom actuator where bucket tip velocity is relatively greater and output increased velocity commands to the boom actuator where bucket tip velocity is relatively less.